Segmental torso masses and joint torques produced by gravity in the adolescent scoliotic spine

Introduction Calculating segmental torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. Methods Low dose CT data was used to calculate vertebral level-by-level torso masses and spinal joint torques for 20 female AIS patients (mean age 15.0 ± 2.7 years, mean Cobb angle 53 ± 7.1°). ImageJ software (v1.45 NIH USA) was used to threshold the T1 to L5 CT images and calculate the segmental torso volume and mass for each vertebral level. Masses for the head, neck and arms were taken from published data. Intervertebral joint torques in the coronal and sagittal planes at each vertebral level were found from the position of the centroid of the segment masses relative to the joint centres (assumed to be at the centre of the intervertebral disc. The joint torque at each level was found by summing torque contributions for all segments above that joint. Results Segmental torso mass increased from 0.6kg at T1 to 1.5kg at L5. The coronal plane joint torques due to gravity were 5-7Nm at the apex of the curve; sagittal torques were 3-5.4Nm. Conclusion CT scans were in the supine position and curve magnitudes are known to be smaller than those in standing. Hence, this study has shown that gravity produces joint torques potentially of higher than 7Nm in the coronal plane and 5Nm in the sagittal plane during relaxed standing in scoliosis patients. The magnitude of these torques may help to explain the mechanics of AIS progression and the mechanics of bracing. This new data on torso segmental mass in AIS patients will assist biomechanical models of scoliosis.

A hypothesis test using bias-adjusted AR estimators for classifying time series in small samples

A new test of hypothesis for classifying stationary time series based on the bias-adjusted estimators of the fitted autoregressive model is proposed. It is shown theoretically that the proposed test has desirable properties. Simulation results show that when time series are short, the size and power estimates of the proposed test are reasonably good, and thus this test is reliable in discriminating between short-length time series. As the length of the time series increases, the performance of the proposed test improves, but the benefit of bias-adjustment reduces. The proposed hypothesis test is applied to two real data sets: the annual real GDP per capita of six European countries, and quarterly real GDP per capita of five European countries. The application results demonstrate that the proposed test displays reasonably good performance in classifying relatively short time series.

The renormalization group: A perturbation method for the graduate curriculum

In this paper the renormalization group (RG) method of Chen, Goldenfeld, and Oono [Phys. Rev. Lett., 73 (1994), pp.1311-1315; Phys. Rev. E, 54 (1996), pp.376-394] is presented in a pedagogical way to increase its visibility in applied mathematics and to argue favorably for its incorporation into the corresponding graduate curriculum.The method is illustrated by some linear and nonlinear singular perturbation problems. Key word. © 2012 Society for Industrial and Applied Mathematics.

A survey in mathematics for industry: Two-timing and matched asymptotic expansions for singular perturbation problems

Following the derivation of amplitude equations through a new two-time-scale method [O'Malley, R. E., Jr. & Kirkinis, E (2010) A combined renormalization group-multiple scale method for singularly perturbed problems. Stud. Appl. Math. 124, 383-410], we show that a multi-scale method may often be preferable for solving singularly perturbed problems than the method of matched asymptotic expansions. We illustrate this approach with 10 singularly perturbed ordinary and partial differential equations. © 2011 Cambridge University Press.

Measurement of small ions near a busy motorway

Combustion sources are well-known sources of electrical ions (Howard, J.B. et al. 1973). Motor vehicles emissions are one of the main sources of ions in urban environments. The presence of charged particles in motor vehicle emissions has been known for many years (Kittelson, 1986; Yu et al, 2004; Jung and Kittelson, 2005). Although these particles are probably charged by the attachment of air ions, there is very little information on the nature, sign and magnitude of the small ions (diameter < 1.6 nm) emitted by motor vehicles and/or present by the sides of roads.

Determining gas sampling timelines for estimating emissions in small chamber incubation experiments

A laboratory experiment was set up in small chambers for monitoring greenhouse gas emissions and determining the most suitable time for sampling. A six-treatment experiment was conducted, including a one week pre-incubation and a week for incubation. Timelines for sampling were 1, 2, 3, 6 and 24 hours after closing the lid of the incubation chambers. Variation in greenhouse gas fluxes was high due to the time of sampling. The rates of gas emissions increased in first three hours and decreased afterward. The rates of greenhouse gas emissions at 3 hours after closing lids was close to the mean for the 24-h period.

A benzothiadiazole end capped donor–acceptor based small molecule for organic electronics

A benzothiadiazole end-capped small molecule 3,6-bis(5-(benzo[c][1,2,5] thiadiazol-4-yl)thiophen-2-yl)-2,5-bis(2-butyloctyl)pyrrolo[3,4-c]pyrrole-1, 4(2H,5H)-dione (BO-DPP-BTZ) using a fused aromatic moiety DPP (at the centre) is designed and synthesized. BO-DPP-BTZ is a donor-acceptor-donor (D-A-D) structure which possesses a band gap of 1.6 eV and exhibits a strong solid state ordering inferred from ∼120 nm red shift of the absorption maxima from solution to thin film. Field-effect transistors utilizing a spin coated thin film of BO-DPP-BTZ as an active layer exhibited a hole mobility of 0.06 cm 2 V-1 s-1. Solution-processed bulk heterojunction organic photovoltaics employing a blend of BO-DPP-BTZ and [70]PCBM demonstrated a power conversion efficiency of 0.9%.

Small firms and the challenge of equality, diversity and difference

Purpose The purpose of this paper is to introduce the papers contributing to this special issue and to locate them within the broader questions about the role of small firms in enabling or alleviating issues of equality, diversity, and difference for various groups in society. Design/methodology/approach The literature dealing with the issues of equality, diversity, and difference pertaining to the operation of and/or working in smaller firms was reviewed prior to drawing out the key points from the submitted papers and considering the contribution they make to this literature. Findings Overall, one's these five papers contribute to one's understanding of the issues facing those in business or self‐employment, working in small business or wanting to pursue enterprise. Originality/value Rarely are questions asked about the assumed role small firms play in mitigating social exclusion for a range of groups in society. By addressing questions which explore the challenge of equality, diversity, and difference for small business in their establishment, management, and effective operation using interdisciplinary frameworks and different methodologies, a better understanding of the role of small business in society can be developed.

Small firms and health and safety harmonisation : potential regulatory effects of a dominant narrative

Small firms are popularly viewed as resistant to complying with regulation. Harmonisation of Australia’s state-based work health and safety regimes is a significant regulatory change. In this article, we consider the likely responses of small firms to work health and safety harmonisation and argue that a range of choices are open to small firm owner-managers. These choices are shaped by individuals’ world views and are influenced by elements in the firms’ context. A significant element is the public narrative of work health and safety harmonisation, which can be understood by using discourse and sense-making concepts. Our analysis of small firm owner-manager choices takes into account small firms’ embeddedness in their regulatory context and the influence on organisational decision-making of the narrative of work health and safety harmonisation. The dominant narrative is arguably silent on the benefits of the work health and safety regulatory change and therefore the response of small firms is likely to be avoidance or minimalism. Non-compliance could be the result due to poor awareness of opportunities arising from this regulatory change.

Small firms, the paid maternity leave debate in Australia and the business case

Purpose The purpose of this paper is to examine the management of maternity leave in small firms and particularly to explore the perceived costs and benefits of paid maternity leave (PML). PML is a universal right in some countries (i.e. the UK), but not in Australia where most private sector female employees only have access to 12 months unpaid maternity leave. It also aims to explore how the business case for (or against) PML is constructed in small firms. Design/methodology/approach The study was limited to smaller firms operating in the business services sector in the same regional area. Semi‐structured interviews were conducted with eight employers and female employees in six of these firms. Analysis by theme was undertaken within and across interview transcripts. Findings Not one of these small firm employers offered PML and the cost of doing so was not considered to outweigh the benefits already realised through the (legislated) unpaid maternity leave scheme. In these firms maternity leave was managed in an informal way with notions of flexibility – give and take – characterising what happens. Originality/value The paper addresses the lack of research on access to family‐related leave policies in small firms. Employer and employee views of the issue are drawn upon, the latter not often being heard. The paper contributes to understanding the construction of the business case for a specific issue in smaller firms and human resource management from a resource‐based view more generally in smaller firms.

Understanding financial information used to assess small firm performance : an Australian qualitative study

Purpose The purpose of this paper is to investigate the reality of financial and management accounting in a small group of small firms. Specifically, from the owner's perspective, an exploration is undertaken to see what financial information is collected, how it is used (or not) to make business decisions and evaluate the firm's performance, and the role played by the accountant in that process. Design/methodology/approach A phenomenological paradigm underpins this exploratory study. Semi‐structured interviews were undertaken with the owners of ten small firms, where the focus was on understanding what happens in an organisational setting, as opposed to theory and textbook practice. Findings The qualitative data supported prior research in other countries. The in‐depth analysis revealed a very basic understanding of accounting information and problems with the financial literacy amongst these small firm owners. Accounting reports were not widely produced or used, so an informal assessment, such as how much cash was in the bank, was the primary means of assessing business performance. Accountants were used for taxation services, although some owners sought more general business advice. Originality/value An understanding is developed of why there might be a gap between textbook rhetoric and reality of accounting practice in small firms. The conclusion is that accounting textbooks need to include more information about the reality of financial management in small firms.

Informal e-learning : the case of small business owners

Purpose - The purpose of this paper is to investigate the use of an informal online discussion forum (ODF) to encourage voluntary participation and promote double-loop learning by small business owners (SBOs). Design/methodology/approach - A qualitative methodology was used where data gathered from three sources, the ODF posts, in-depth interviews with participants and a focus group with non-participants. These were analysed to evaluate learning of SBOs in an ODF. Findings - This research provides evidence that an ODF for SBOs supports double-loop learning; however, participation could not be assumed simply by the online availability of the discussion resource. Research limitations/implications - Few SBOs participated in the ODF which is consistent with research finding SBOs are a difficult group to engage in learning. Four forms of data were analysed to strengthen results. Practical implications - Caution should be exercised when considering investment in e-learning for SBOs. Originality/value - Evidence showing e-learning through an informal voluntary ODF can promote deep learning for SBOs.

The Formality and Informality of HRM Practices in Small Firms

The formality and informality of HRM practices in small firms Rowena Barrett and Susan Mayson Introduction The nature of human resource management in small firms is understood to be characterized by ad hoc and idiosyncratic practices. The liability of smallness (Heneman and Berkley, 1999) and resource poverty (Welsh and White, 1981) presents unique challenges to managing human resources in small firms. The inability to achieve economies of scale can mean that implementing formalized HRM practices is costly in terms of time and money for small firms (Sels et al., 2006a; 2006b). These, combined with small firm owner–managers’ lack of strategic capabilities and awareness (Hannon and Atherton, 1998) and a lack of managerial resources and expertise in HRM (Cardon and Stevens, 2004) can lead to informal and ad hoc HRM practices. For some this state of affairs is interpreted as problematic as the normative and formalized HRM practices in the areas of recruitment, selection, appraisal, training and rewards are not present (see Marlow, 2006 and Taylor, 2006 for a critique). However, a more nuanced analysis of the small firm and its practices in their context can tell a different story (Barrett and Rainnie, 2002; Harney and Dundon, 2006). In this chapter we contribute to our understanding of small firm management practices by investigating a series of questions in relation to HRM in small firms.

The relationship between small firm growth and HRM practices

The relationship between small firm growth and HRM practices Rowena Barrett, Susan Mayson and Niel Warriner Introduction In this chapter we explore the relationship between small firms’ growth orientation, their business planning efforts and the role the owner plays and whether or not formal HRM practices are used. Formal HRM practices are assessed in terms of whether they are written down, regularly applied or assured to take place. We take on board Heneman et al.’s (2000) suggestion that ‘surveys of employer practices across SMEs [would] be [a] valuable addition to the strategic human resource management literature’ (p. 23) and report the results of an online and paper survey of a sample of 1753 small firms (defined as those employing less than 20 people) in the state of Victoria (SE Australia). Our particular interest in this chapter, which is based on an analysis of 410 responses to the survey, is whether growthoriented small firms adopt formal HRM practices. This research contributes to understanding whether more formal organizational systems and routines are more likely to be used (or not) to nurture human capital in growth-oriented small firms. Moreover by focusing on firm growth, this chapter, consistent with recent calls in the literature (see Baron, 2003; Barrett and Mayson, 2006; Katz et al., 2000; Tansky and Heneman, 2003), contributes to a better understanding of issues at the intersection of entrepreneurship and HRM research.